I have a custom board with the TM4C1294NCPDT. The Ethernet interface works fine using the lwIP library. When I execute f_mount( ) to initialize access to the uSD card I start to see TCP (re-transmissions and duplicate ACK) errors using Wireshark. No other card accesses are done other than the f_mount. If I remove the card from the socket I can call f_mount and all is OK. I could not find any "hidden" accesses to the card or any interrupts running that may cause timing issues.
Any suggestions on where to look would be appreciated.
Thanks,
Jeff